Definitely no way there would be "multiple" US Grand Prix when the number of European races in a season is less than half.

By the context of the article, seems to be the announcement on Tuesday will be showing the world the proposal of the NJ Grand Prix that will be submitted to the FOM and upon its approval.

Don't fool yourself, the ammount of money they would "miss out on" by limiting themselves to one grand prix in the US would be significant. Something in north jersey would bring in an INSANE ammount of cash.